(a) Field of the Invention
The present invention relates to an apparatus for injecting liquid crystal materials and methods for manufacturing liquid crystal panels by using the same.
(b) Description of the Related Art
In general, a liquid crystal display (LCD) has two substrates having electrodes and a liquid crystal layer between the two substrates. The substrates are adhered to each other by a sealant deposited at the edges of the substrates, and are supported by spacers dispersed between the substrates. Different electrical potentials are applied to the electrodes while forming electric fields for varying the orientation of the liquid crystal molecules. In this way, the light transmission is controlled to thereby display picture images.
To manufacture this LCD, an alignment layer to align the liquid crystal molecules is formed and rubbed. Then, spacers are dispersed on the inner surface of one of the two substrates, and the sealant having an injection hole is deposited on the inner surface of one of the substrates near the edge of the substrate. Next, the two substrates are adhered to each other through a hot press process, and a liquid crystal material is injected into the cell gap between the two substrates through the injection hole to form a liquid crystal layer. Finally, a liquid crystal cell is completed by filling the injection hole with a sealant.
Here, the process of injecting the liquid crystal material will be described in detail.
First, a tray containing the liquid crystal material and liquid crystal panel is loaded into an airtight filling chamber, and a high vacuum is developed inside of the chamber. Next, the injection hole of the liquid crystal panel is completely immersed in the liquid crystal material, and then the inside of the filling chamber is gradually returned to atmospheric pressure. In that case, the liquid crystal material is injected into the cell gap between the two substrates through the injection hole.
However, in a conventional method for manufacturing the conventional LCD, the process of injecting the liquid crystal material takes a long time, because the liquid crystal material is injected through a narrow injection hole under vacuum. Generally, the injecting process of a 17 inch liquid crystal panel takes about 12 hours, and it is difficult to mass-produce a smectic liquid crystal panel having a narrower cell gap by using this injecting process. Furthermore, as the cell gap is reduced to less than 2 μm, the injecting process time in this manufacturing method suddenly increases.